Rapid assessment of seasonal in-field water management on micro irrigated annual and perennial crops in Central Italy. Graziano Ghinassi and Stefano Cecchi University of Florence – Italy 7th Asian Regional Conference June 27, 2012 – Adelaide, Australia

Triennial research project on irrigation sustainability (S.E.Agr.I.T.) supported by the Regional Agency for Development and Innovation in the Agricultural and Forest Sector (ARSIA) of the Tuscan Region. The project was carried out in the main irrigated areas of Tuscany. the project

main irrigated areas in tuscany

investigated 1,200 ha of irrigated crops

Investigate on-farm water use and management, in order to define guidelines for improving efficiency of irrigation water use at different scales aim of the project

-University of Florence: Department of Hydraulics Department of Soil Sciences and Plant Nutrition Department of Agricultural Economics -University of Pisa: National Laboratory of Irrigation, LNI (standard testing and certification of irrigation equipments) project partners-universities

project partners-professional associations -Professional Associations of Farmers: ERATA IRIPA CIPA-AT -Tuscan Regional Union of Water User Associations (URBAT)

Sample of 40 irrigated farms selected according to representative criteria:  size  cultivated crops  irrigation type  tenancy  labour  management Selection supported by the professional Associations farms sample

Composed of progressive steps on assessment and measurements of:  water withdrawals  crop water requirements  energy use  agronomical and economical evaluation of the farming practices project arrangement

Intermediate step at irrigation unit level (on 18 farms):  measurement of working characteristics and performance of the irrigation system;  hydrological characterization of the soil;  monitoring of crop and climate evolution through the season. project arrangement

1. system performance and irrigation management  Lab and field measurements (nominal to actual discharge);  Irrigation to avoid deficit irrigated zones.

Nominal discharge does not allow correct estimate of the average discharge of driplines Nominal DRIPLINE MODELdischarge AverageMaxMinDUlq (l/h·m) (%) Model From bench test at LNI From field measure Modello From bench test at LNI From field measure Model From bench test at LNI From field measure Model From bench test at LNI From field measure ………….….. ………………..….….. Lab and field measurements (nominal to actual discharge)

Actual DUlq is below the potential as calculated according to the LNI bench results Nominal DRIPLINE MODELdischarge AverageMaxMinDUlq (l/h·m) (%) Model From bench test at LNI From field measure Modello From bench test at LNI From field measure Model From bench test at LNI From field measure Model From bench test at LNI From field measure ………….….. ………………..….….. Lab and field measurements (nominal to actual discharge)

Dripline length (m) Depth (cm) Infiltrated water Active rootzoneAverage infiltration Soil water infiltration along a dripline on flat ground USED BY THE CROP WASTED Effective and inefficient irrigation irrigation to avoid deficit irrigated zones

2. scope of the presentation Describe an approach to investigate and assess in-field management of micro irrigation

3. materials & methods Measurement and assessment on: 3.1 DUlq target 3.2 Seasonal Net Irrigation Requirement (NIR) 3.3 Seasonal Irrigation Supply (SIS) 3.4 Irrigation performance - relative surplus

3.1 DUlq target  DUlq target= reasonable minimal target threshold of DUlq, set equal to 90% for irrigation of both annual and perennial crops, taking into account average farming conditions, cropping patterns and farmers skills;  DUlq target compared to values measured in the irrigation units;  Assessment of water supplied by system operating at DUlq target (IS DU90 ).

3.2 Seasonal Net Irrigation Requirement (NIR)  Calculated through the daily water budget referred to the soil depths explored by the active root system during the season;  Crop evapotranspiration (ETc) calculated by using the Eto FAO-Penman- Monteith equation and site specific crop coefficients (kc);  Effective rainfall (ER) assumed to be ≥5mm;  On mulched crops, total ETc and ER were reduced;  Climatic data yielded by meteorological stations which are part of the Agrometeorological Service of ARSIA.

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3.3 Seasonal Irrigation Supply (SIS) Seasonal irrigation supply on each micro irrigated unit estimated according to: -actual discharge under average working conditions (e.g., operating pressure); -irrigation time during the season.

3.4 Irrigation performance - relative surplus  relative irrigation surplus, either positive or negative, depending on system performance: where: TRS= Technical Relative Surplus (%); SIS= Seasonal Irrigation Supply (mm); IS DU90 = Irrigation Supply under the target DUlq (mm).

3.4 Irrigation performance - relative surplus  relative irrigation surplus, either positive or negative, depending on on-farm management: where: MRS= Management Relative Surplus (%); SIS= Seasonal Irrigation Supply (mm); NIR= Net Irrigation Requirement (mm).

3.5 simplified water balance NIR/DUlq ratio is the traditional approach to represent Gross Irrigation Requirement (GIR) to apply; Evaluation of the components that over the season enter and leave the field allows to assess:  Efficiency of irrigation practice (NIR/SIS);  Effectiveness of Irrigation Management (SIS/GIR), under actual conditions.

Fates of water applied

Fates of water applied under drip irrigation

4. results and discussion-annual crops

4. results and discussion-perennial crops

4. results and discussion-farmers’ self evaluation annual CROPTRS (%) MRS (%) TSEMSE Tomatoes046adequate Watermelon824adequate Courgette5248adequate Tomatoes1041adequatehigh Melon53highadequate Tomatoes141adequate Celery878adequate Tomatoes66203highadequate Melon11148adequate Watermelon1069adequate Melon52103adequate AVERAGE2073

4. results and discussion-farmers’ self evaluation perennial CROPTRS (%) MRS (%) TSEMSE Vineyard-30high Apple-3-6adequate Apple1626adequate Apple11-70adequate Peach4310adequate Apple10026adequatelow AVERAGE27-2

5. conclusions  Difference between nominal and actual discharge can affect irrigation efficiency and wastes of water, fertilizers and energy.  Farmers seem to pay little attention to system performance, especially when irrigating annual crops.  Poor technical performance not balanced by management in most cases, as indicated by the surplus indexes.  Farmers’ evaluation about on-farm irrigation seems to be based on yield response rather than on water use.

5. conclusions  Good technical and management performance on units adopting saving strategies, such as mulching, or devoted to typical crops such as Vineyard.  System DUlq is below the expected threshold.  Irrigation efficiency is far below the potential in the project areas.

Thank you for your attention